Here are a few pics of the new and improved Bear after the midair. I have about 15 flights on it since the rebuild. New fuse and tail feathers, everything else is from the original RB. Two bladed prop does not have the same presence as the 3 bladed one, but the 2 bladed one is certainly alot faster.

Yes, this link is from Sweden.
This is the builder of my Bare hows writing about the crappy tail on the RB, just to inform others.

This is how my stab looked like after 5 min of flying!!!

AndreasE,
Sorry about your loss. Kinda looks like none of the tail mods were done. Anyway, the red lines outline perfectly how the arrowshafts in the tail need to be. The green arrow points to where I installed a 1 inch thick rib on each side and also dont forget to gorilla glue it after that. I also didnt open up either one of my stabs, it isnt necessary.

AD Clark III,
Are you saying that you didn't open your stabs on your second Rare Bear?

Cat5752,
I actually didnt open up either one of them.
Yesterday I was at the field with RB #2 making approx a 130mph pass when I heard a sharp crack and my Horiz stab began to flutter violently. The airplane pitched up and I didnt have any elev control, I chopped the throttle and it went deadstick straight in from about 100 feet. The airplane did not lose any parts while fluttering, both horiz stabs stayed attatched.
Closer inspection revealed that both arrowshafts in the stab(where they pass through the fuse) had snapped! I took one of the stabs and cut it open on the bandsaw so you can have a look at my mods.
1. arrowshafts have been lengthened
2. gorilla glue in all panels
3. Rib at the stab root is made out of plywood and maple(approx 1 inch wide)outlined in blue marker.
Who would of thought the weak link in the stab would be the arrowshafts? Anyway, I had a good time with my RB and if you keep the speed in the 120mph and below range its a great airplane with the mods. BTW..I was running an APC two bladed 15x11 prop on a OS 160 at 9400 rpm. So..I guess I am outa the RB business for now. Later

Ad Clark...

That sounds very bad in both ways you out of the rb business, because i enjoyed your explanation ,the good info with pics and bad that your nice rb is gone , hope you had a chance to safe some parts engine rc and so on.

what was the material of the both arrowshafts fiberglass or cfk, i think a good idear is build the rods in cfk big as possible around 10-12 mm or 14mm if it fits in the ribs and from left to right in one pice .
and bigger arrowshafts made of cfk in the fuse to support the shafts.

it looks to me that i will have to do bigger mods to my next summer rb than just adding some glue...... cfk shop i am comming

cheers
michael

The arrows cracked? Thats crazy! I am almost finished with my Bear after more than a year and now....I don't really want to fly it unless I just gingerly coast around in plain ol' circle pattern at slow speed[&o]

The arrows cracked? Thats crazy! I am almost finished with my Bear after more than a year and now....I don't really want to fly it unless I just gingerly coast around in plain ol' circle pattern at slow speed[&o]

Thats what I think as well. Those were carbon fiber arrowshafts. I couldnt break that stab with both hands on the ground if I tried. I guess there some pretty unbelievable forces acting on that stab in flight. I wasnt radaring it the time of failure but based on previous flights that day it was doing about 130 in straight and level flight when the stab let go. Its got me scratching my head. I guess if I ever build another one I will have to make the spars out of titanium.
I concede, the RB has given me a good ol fashion woodshed beating.

Man, it's just one thing after another with this bird - most of which seem to be major design flaws (not that Thunder Tiger cares).

I'm about to the point I'll just go fly it till it crashes, and hope I can save my motor - then perhaps move on to a World Models GS. Or perhaps I could just take all my stuff out of it now, and hang it from the ceiling, that would be safer for the spectators...

Hey guys....
Sorry to hear about the Bears going down. Mine has also self destructed. I'll save all the gory details for now, but I do have some opinion on the stab issue. I think that a big problem lie in the Fiberglass fuse, especially in the area where the stab glues to it. I believe that under force, or lift, the fuse is too flexible and thus acting like a spring, bounceing or springing up and down. I know this may sound crazy, as it is just an educated guess hypothosis.
Knowing what I know now, if I were to want to actually fly this bird as a sport model, I would go for scale looks and forget the speed. Slow this baby down to under 90 MPH. Or just strip it and hang it up. save your gear.
FWIW

Dudley

it does make a really purty static display model, doesn't it?

(kind of expensive for a static display model tho)

I think thats just bad carbon fiber material, if you want strong stuff go with full carbon rods big as possible in dia and it will hold.
i am currently here in germany and i will go with this material here http://www.carbon-team.de/rohre-stä...d-c-23_32.html

if you go with an 8 to 10mm full material carbon fiber rod you need lots of force to brake this.
ok..... at 160 mph or more the rods will last in the fuse and the wooden ribs and cover will be gone
cheers
michael

[link]http://www.carbon-team.de/rohre-stäbe-profile-carbonstab-rund-c-23_32.html[/link]

That looks like good stuff their Easystern.(now you show me) A definate must for my next RB. Maybe next year I will get another one once I get the itch again. Got a Kingcat and a phantom to finish up first. Good luck

Wow, Ad Clark III,

After seeing those pictures, I am definitely going to re-do the stab like I said in a much earlier post. I'm going to rebuild the stab out of foam core, wood and glass as one piece all the way through the rear of the fuselage. While I have the rear end opened up, I'll strengthen the rear of the fuse, too.

I am no longer going to consider this as an ARF and I'll rebuild it taking into account all the build mods and flight testing you guys have all done. You guys may have some broken airplanes but you definitely helped those of us who haven't started building ours yet.

Thanks to you all
Don

Any one having trouble with the wing tube being to tough to get the wing up all the way?Thanks Todd

Yes, I had that problem too.

This is not a ARF, this is crap

Some questions from the UK,
Has anyone built and flown this with the recommended engine size? It seems that many of the builders are using larger engines and I would be interested in anyone using the usual powerplant. And what is gorilla glue?? Never heard of it over here.
Al

Willyuk
Gorrila glue is an alphatic pva glue, if attaching a canopy is your question use a simple pva wood glue, but be patient as it take some time to cure under a non porus surface.
Mike

Thanks for that, it wasn't about canopies but due to numerous people on this thread who seem to use gorilla glue all over the place to strengthen rib joints and the like. I wondered if it was some very clever expanding foam sort of job.

Yep......I added a 50/50 mix of water to gorilla glue in a cup. I then quickly stirred it, sucked it into a syringe(without needle) and then injected into my stab. As the gorilla glue expands, it comes right back out of the hole I injected it into. The glue will continue to expand for approx 5 minutes. Have paper towels and rubbing alcohol at the ready for the clean up.
BTW....I would not use gorilla glue as a glue, I would only use it as a filler, like I did in this stab. Even after the gorilla glue is dry, I could poke my fingers into it like foam. The glue I used was BVM aeropoxy....when it dries, it is rockhard. Good luck

I have been reading all the past threads from all the many modelers from all across the world and everyone has had a problem with this plane. I am still waiting for ACE an or Thunder Tiger to send me my money. I figure they owe me nearly a thousand bucks for everything involved including the many hours I spent wasting my time with their junk they call an airplane. I eventually made a nice boat anchor out of the crashed carcuss. Interestingly enough it has worked more times as a boat anchor than it did as an airplane. People are still having a problem correctly building the plane so that it won't fall apart in the air. I asked the guys at ACE to call me when they built one exactly as stated in the plans and then flew it more than 4 flights without a problem with it falling apart. This was about 8 months ago... They have not called me yet. I am still waiting for my money back. I still have not purchased so much as a screw from those folks and I don't plan to until they make things right.

Hi Im steve in the UK , Looking at your bear, nice job ,I found the decals on the canopy are poor ,they spoil the finish so Iv masked and sprayed mine with flair gloss white fuel proof paint and the finish is first class. You wouldnt be disapointed with the result. All members at the field love it .....Im flying mine with the TTpro90 engine and a 13 x 7 master airscrew and she's a babe.
Chocks away ..............

Congrats there Biggles2,
Had I kept the speed below 120 mph, I would still be flying mine as well. I guess I was having too much fun racing the lil toni's and the shoestrings and my RB speed crept up into the low 130's. I believe Vne for this aircraft is 120 mph with all of the mods. Despite having to do all the mods, it was still a great flying aircraft.